Derivative Financial Instruments - Schedule of Derivative Financial Instruments on Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Derivative [Line Items]
Derivatives in hedging relationships	$ 1,520	$ 2,100	$ 4,337	$ 4,472
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivatives in hedging relationships	2,018	2,464	4,039	4,914
Designated as Hedging Instrument [Member] \| Interest And Fees On Loans [Member] \| Interest Rate Contracts [Member] \| Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives in hedging relationships	2	(1)	4	(3)
Designated as Hedging Instrument [Member] \| Interest on long-term borrowings [Member] \| Interest Rate Contracts [Member] \| Cash Flow Hedging [Member]
Derivative [Line Items]
Derivatives in hedging relationships	2,016	2,465	4,035	4,917
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	(498)	(364)	298	(442)
Not Designated as Hedging Instrument [Member] \| Income from Mortgage Banking Activities [Member] \| TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	(489)	(403)	(8)	(841)
Not Designated as Hedging Instrument [Member] \| Income from Mortgage Banking Activities [Member] \| Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	(27)	0	321	335
Not Designated as Hedging Instrument [Member] \| Income from Mortgage Banking Activities [Member] \| Forward Loan Sale Commitments [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	$ 18	$ 39	$ (15)	$ 64